(a) Technical Field
The present invention relates to a hydrogen supply system for a fuel cell and a method for controlling the same. More particularly, the present invention relates to a hydrogen supply system including a plurality of hydrogen tanks, in which an in-tank regulator is mounted on one hydrogen tank and a solenoid valve is mounted on each of the other hydrogen tanks so as to stably supply hydrogen by controlling the solenoid valves during driving, and a method for controlling the same.
(b) Background Art
Generally, a fuel cell system includes a fuel cell stack for generating electrical energy, a fuel (hydrogen) supply system for supplying fuel (hydrogen) to the fuel cell stack, an air supply system for providing oxygen in the air to the fuel cell stack, the oxygen in the air being an oxidizer required for an electrochemical reaction, and a thermal management system for controlling the operating temperature of the fuel cell stack.
Hydrogen compressed to a high pressure of about 350 bar is stored in a hydrogen tank in the fuel supply system. The stored compressed hydrogen is discharged to a high pressure line according to an on/off of a solenoid valve preferably provided at an inlet portion of the hydrogen tank and then supplied to the fuel cell stack after the pressure of the compressed hydrogen is reduced from 350 bar to 10 bar by an external regulator.
Preferably, as a method of storing hydrogen in the hydrogen tank of the fuel cell system, a high pressure compression (350 bar or 700 bar compression) method is generally adopted. Accordingly, a high pressure of 350 bar or 700 bar is always applied to the high pressure line connected to the solenoid valve by the use of the external regulator, thus affecting the durability of the portions to which the high pressure is continuously being applied.
Given the above circumstances, when an in-tank regulator is used instead of the external regulator, it is possible to ensure safety during operation of the system by eliminating the high pressure line, and further it is possible to simplify the system and reduce manufacturing cost.
The in-tank regulator is effective for a single tank system; however, in the case of a multiple tank system including a plurality of tanks, the manufacturing cost of the in-tank regulator is increased since it should be provided at each of the plurality of tanks.
Accordingly, a large-scale single tank system is employed; however, it is necessary to optimally design a space for mounting the large-scale single tank in the vehicle body and chassis, and it is difficult to pack the single tank with peripheral components due to the large volume.
Accordingly, the multiple tank system, in which a plurality of small-scale tanks is mounted, provides a degree of freedom for the vehicle body and chassis design and can be packaged with the peripheral components, as compared with the single tank system. Further, the multiple tank system has a reduced manufacturing cost.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.